Electric Double-Layer Capacitor (EDLC)Simplified SPICE Behavioral Model

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LTspice Version

Bee Technologies

Contents

1. Benefit of the Model

2. Model Feature

3. Concept of the Model

4. Parameter Settings

5. Electric Double-Layer Capacitor (EDLC) Specification (Example)

5.1 Charge Time Characteristic

5.2 Discharge Time Characteristic

Simulation Index

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1. Benefit of the Model

• The model enables circuit designer to predict and optimize Electric Double-Layer Capacitor (EDLC) runtime and circuit performance.

• The model can be easily adjusted to your own EDLC specifications by editing a few parameters that are provided in the datasheet.

• The model is optimized to reduce the convergence error and the simulation time

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• This EDLC Simplified SPICE Behavioral Model is for users who require the model of a EDLC as a part of their system.

• Capacitor Voltage(Vcap) vs. Time (s) Characteristic, that can perform EDLC charge and discharge time at various current rate conditions, are accounted by the model.

2. Model Feature

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Equivalent circuit of Electric Double-Layer Capacitor (EDLC) model

3. Concept of the Model

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EDLCSimplified SPICE Behavioral Model

[Spec: VRATE,VINT,CAP,ESR,TSCALE]

+

-

• The model is characterized by parameters: VRATE which represent the Rated Voltage, CAP which represent the capacitor capacity and VINT which represent the capacitor initial capacity level.

• Open-circuit voltage (VOC) vs. Time (s) is included in the model as an analog behavioral model (ABM).

Output Characteristics

4. Parameter Settings

VRATE is the Rated Voltage [V]– e.g. VRATE = 1, 4.2, or 5.5 [V]

VINT is the Initial Condition– e.g. VINT =0 for a empty capacitor (0%), VINT=4.2 (equal VRATE)

for a full charged capacitor (100%)

CAP is the capacitance [F]– e.g. CAP = 0.1, 0.47, or 10 [F]

ESR is the equivalent Series Resistance of capacitors– e.g. ESR = 0.1, 0.5, or 1 []

TSCALE turns TSCALE seconds into a second– e.g. TSCALE=60 turns 60s or 1min into a second, TSCALE=3600

turns 3600s or 1h into a second

• From the EDLC specification, the model is characterized by setting parameters VRATE, VINT, CAP, ESR and TSCALE.

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Model Parameters:

(Default values)

5. Li-Ion Capacitor Specification (Example)

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Rated voltage, VINT, capacitance and ESR are input as a model parameter

Rated voltage, VINT, capacitance and ESR are input as a model parameter

Rated Voltage 4.2V

Capacitance 0.47F

ESR 0.13

5.1 Charge Time Characteristic

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(second)

Measurement Simulation

• Rated Voltage: 4.2V• Initial Condition: 0V• Charging Current: 1A

25C

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

0 0.5 1 1.5 2 2.5

Capa

cito

r V

olta

ge(V

)

Time(s)

Charge Time Chracteristic

V

5.1 Charge Time Characteristic Simulation Circuit and Setting

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Charging CurrentCharging Current

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Measurement Simulation

• Rated Voltage: 4.2V• Initial Condition: 4.2V• Discharging Current: 1A

5.2 Discharge Time Characteristic

(second)

25C

5.2 Discharge Time Characteristic Simulation Circuit and Setting

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Discharging CurrentDischarging Current

Simulation Index

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Simulations Folder name

1. Charge Time Characteristic.................................

2. Discharge Time Characteristic.............................

Charge_Time

Discharge_Time